Walnut Grove is a town in Leake County, Mississippi. The population was 1,911 at the 2010 census. Under the leadership of eight-term mayor, William Grady Smith, one of the longest-serving mayors in the state, the town in the early 2000s dramatically increased its population and revenues by annexing the Walnut Grove Youth Correctional Facility, which had been privately owned and operated since 2001 under a contract with the state Department of Corrections.
According to the United States Census Bureau, the town has a total area of 0.8 square miles (2.1 km²), all land.
As of the census of 2000, there were 488 people, 215 households, and 127 families residing in the town. The population density was 610.2 people per square mile (235.5/km²). There were 239 housing units at an average density of 298.9 per square mile (115.3/km²). The racial makeup of the town was 57.38% White, 40.78% African American, 0.20% Native American, 0.20% Pacific Islander, and 1.43% from two or more races. Hispanic or Latino of any race were 0.41% of the population.
There were 215 households out of which 31.6% had children under the age of 18 living with them, 35.3% were married couples living together, 20.9% had a female householder with no husband present, and 40.5% were non-families. 36.7% of all households were made up of individuals and 14.9% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 3.00.
In the town, the population was spread out with 29.1% under the age of 18, 6.8% from 18 to 24, 26.0% from 25 to 44, 22.5% from 45 to 64, and 15.6% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 86.3 males. For every 100 females age 18 and over, there were 79.3 males.
The median income for a household in the town was $21,719, and the median income for a family was $27,981. Males had a median income of $21,667 versus $26,000 for females. The per capita income for the town was $11,851. About 25.2% of families and 29.8% of the population were below the poverty line, including 47.1% of those under age 18 and 15.1% of those age 65 or over.
The 2006 population estimate had 1,424 residents; this dramatic increase is due to the annexation of the Walnut Grove Correctional Facility and its inmate population. The continued growth through estimates for 2016 largely represented additional inmate population.